package security;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.springframework.security.access.SecurityMetadataSource;
import org.springframework.security.access.intercept.AbstractSecurityInterceptor;
import org.springframework.security.access.intercept.InterceptorStatusToken;
import org.springframework.security.web.FilterInvocation;

public class MySecurityInterceptor extends AbstractSecurityInterceptor implements Filter {

	//安全源数据
	private SecurityMetadataSource securityMetadataSource;
	
	public SecurityMetadataSource getSecurityMetadataSource() {
		return securityMetadataSource;
	}

	public void setSecurityMetadataSource(
			SecurityMetadataSource securityMetadataSource) {
		this.securityMetadataSource = securityMetadataSource;
	}

	@Override
	public Class<? extends Object> getSecureObjectClass() {
		return FilterInvocation.class;
	}

	@Override
	public SecurityMetadataSource obtainSecurityMetadataSource() {
		return this.getSecurityMetadataSource();
	}

	public void destroy() {
		
	}
	
	//实现方法，每当一对request/response对 通过chain时就会被调用
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		  FilterInvocation fi = new FilterInvocation(request, response, chain);
	      invoke(fi);
	}
	
	//Causes the next filter in the chain to be invoked
	public void invoke(FilterInvocation fi) throws IOException,
		ServletException {
		InterceptorStatusToken token = super.beforeInvocation(fi);
		try {
		    fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
		} finally {
		    super.afterInvocation(token, null);
		}
	}
	

	public void init(FilterConfig arg0) throws ServletException {
	}

}
